A-POSTERIORI ERROR ESTIMATION FOR FULLY DISCRETE HIERARCHICAL-MODELS OF ELLIPTIC BOUNDARY-VALUE-PROBLEMS ON THIN DOMAINS

A posteriori error estimators for fully discrete hierarchic modelling on thin domains are derived and are shown to provide computable upper bounds on the discretization error and on the tc,tal error. The estima tors are shown to be robust and do not degenerate as the thickness of the domain tends to zero. If the discretization part of the error is n egligible, the estimator for the modelling error reduces to the one re cently obtained for semi-discrete hierarchical modelling by Babuska an d Schwab.